In yeast, transcription of tRNA genes can act as replication fork barriers and lead to chromosome breakage, although the exact mechanism is not clear. Schultz and coworkers now show that checkpoint proteins specialized for signaling replication stress repress tRNA gene transcription during normal cell proliferation and in genotoxin-treated cells. Based on these findings they suggest that the fork-pausing activity of tRNA genes is regulated by the checkpoint system that has evolved to control replication.
- Vesna C Nguyen
- Brett W Clelland
- Michael C Schultz
